Referring initially to FIG. 1A, illustrated is a plan view of a conventional power strip with first and second power converters plugged into selected outlets. A conventional power strip 100 comprises a male three-prong electrical plug 110, a power cord 120, a receptacle housing 130, and a plurality of female electrical receptacles, generally designated 140 and individually designated 140a-140f. The conventional power strip may also comprise an on/off switch 143 and a circuit breaker/reset button 144. While the number of female electrical receptacles 140 may vary from as few as two or three to perhaps as many as eight, a large percentage of available power strips 100 generally have six receptacles 140. The receptacles 140 have an inter-receptacle spacing 145. With respect to the inter-receptacle spacing 145, the illustrated power strip 100 is representative of standard duplex wall outlets, most outlet multipliers, and many power strips, power centers and uninterruptable power systems commonly in use with personal computers, telephone systems, high-fidelity and television systems, home and commercial satellite receiver systems, etc. These electrical devices are generally sized with about a 1½″ edge-to-edge spacing 145. Although the illustrated embodiment is of a “ground-down” configuration with respect to the power cord 120, a “ground-up” configuration may also be found. Also, the illustrated embodiment is that of a 3-conductor grounded system; two wire systems including polarized outlets 140 and plugs 110 may also be found.
Two power converters 150, 160 are shown installed in outlets 140a and 140f respectively. Although power converters generally vary considerably in size from application to application, i.e., cordless telephone, scanner, battery charger, cellular phone charger, external disk drive, external speakers, etc., most are large enough to block at least one adjacent outlet 140 of a power strip 100. The power converters 150, 160 shown represent the estimated size extremes of a sample of commercially available power converters used with appliances such as listed above.
When only a few devices are plugged into the power strip 100, e.g., only two are shown in FIG. 1A, the loss of one or two outlets 140 due to blockage by an adjacent power converter 150, 160 is not usually a problem. However, as most personal computer users know, the number of devices requiring electrical power at a personal computer installation generally increases over time and, therefore, unusable outlets, for example in FIG. 1A outlets 140b, 140c and 140e, become a problem of wasted resources. One who is skilled in the art will readily observe that the power converter 150 itself obstructs outlet 140b and its secondary power lead 155 effectively obstructs outlet 140c when installed as shown. This location might be necessary if the power converter 150 is equipped with a grounded or polarized plug. When the converter 150 incorporates a polarized or grounded plug, the converter 150 may only be installed in one direction, thus limiting the location of the converter 150 installation to only one or two outlet choices. Clearly, it is recognized that if power converter 150 is the only converter required at that power strip 100 location, one who is of ordinary skill in the art would certainly install power converter 150 in outlet 140f, thereby making the other five of the six outlets useable for other devices employing conventional male three-prong plugs. However, for the sake of this discussion it is assumed that two polarized-plug power converters 150, 160 are required at this location. Thus, the illustrated installation is the least restrictive and most logical in that this installation minimizes the blocked outlets to outlets 140b, 140c and possibly 140e. In this configuration, the size of power converter 160 makes it very difficult to use outlet 140e with a grounded plug. With some converters, because of prong placement or a polarized ground, the location of its secondary power lead 165 may cause outlet 140e to be unuseable. Therefore, the available outlets 140a-140f may be reduced from six to only three useable outlets 140a, 140d, and 140f. Thus, in this illustration, the available outlets 140 of the power strip 100 are reduced by 50 percent. Of course, if at least one electrical device required at this power strip location has only a two-bladed plug, then outlet 140e may also be used.
Referring now to FIG. 1B with continuing reference to FIG. 1A, illustrated is a plan view of an alternative embodiment 101 of the conventional power strip of FIG. 1A. In this embodiment, a conventional power strip 101 comprises outlets 141a-141f that are in the same locations as the outlets 140a-140f of FIG. 1. However, the outlets 141a-141f of FIG. 1B are rotated 90° so that they are in a side-by-side configuration. Inter-receptacle spacing 147 is as close as 1 1/16″ between adjacent outlets, here collectively designated 141. The designs of FIGS. 1A and 1B adequately accommodate a plurality of typical male electrical grounded plugs, similar to the male electrical plug 110, for several appliances required at a single location. As in FIG. 1A, power converters 150, 160 are installed in outlets 141a and 141f, respectively. A common ground orientation, as shown, for the outlets 141 is usually maintained by manufacturers. In this embodiment, the consequences will be the same with both polarized and non-polarized plugs on the converters 150, 160, i.e., outlets 141b and 141e will be blocked. While power converter 160 might be installed in outlet 141d so that both converters 150, 160 block a common outlet 141e, the effect will be the same—only four useable outlets 141a, 141b, 141d, 141f from the original six outlets of the power strip.
It should be noted that other configurations for multiple power outlets are also available on the market. For instance, instead of six outlets 140 in a row as in FIGS. 1A and 1B, outlet configurations also exist of two rows of three outlets each. However, these configurations suffer from the same problems and limitations as detailed above and may, in some instances, have more significant problems for the same reasons.
Traditional solutions to these problems include installing: (a) a different power strip with more outlets, (b) an additional power strip either connected to the wall outlet or to one of the original power strip outlets, or (c) an extension cord with additional outlets. These solutions present four major problems. First, a power strip with more outlets may have outlets that are not really required, clearly at an additional cost over that of the original power strip. Second, a second power strip is additional clutter to what is probably already a nest of cables. The additional power strip may have a significant number of unused outlets or, if plugged into an outlet of the original power strip, might encourage overloading the original power strip or power circuit with an excessive number of appliances. Third, the extra six to ten feet of extension cord is also additional clutter. Fourth, ordinary extension cords for permanent wiring solutions are strongly discouraged by fire and safety experts alike because of the increased fire risk and tripping hazard.
Only recently have power strip and power center manufacturers recognized the problems detailed above and begun to offer solutions. Referring now to FIG. 1C, illustrated is a plan view of a second alternative embodiment 102 of the conventional power strip of FIG. 1A. In this embodiment, the power strip 102 comprises the male three-prong electrical plug 110, power cord 120, a receptacle housing 132, and a plurality of female electrical receptacles, generally designated 142 and individually designated 142a-142f. The approach in this prior art embodiment has been to increase spacing between some of the outlets 142 to allow insertion of power converters 150, 160. Four of the receptacles 142a-142d have a conventional inter-receptacle spacing 145, while receptacles 142e and 142f have a greater inter-receptacle spacing 148 and are separated from the other receptacles 142a-142d by a significant distance 146 that permits better use of all outlets 142. However, the number of spaced-apart outlets, e.g., 142e, 142f, is usually limited to about one-third of the total outlets 142 of a power strip 102 or power center. Therefore, if the number of power converters needed at a single location exceed the number of spaced-apart receptacles 142e, 142f provided on the power strip 102, the problems detailed above remain. Various configurations employing this solution may be currently found on the market.
Accordingly, what is needed in the art is a device that (a) eliminates the outlet blocking problem of power converters, (b) eliminates unnecessary extension cord lengths, (c) is usable with all power strips, receptacles, power centers, etc., and (d) is cost effective.